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Waterjet vs Plasma Cutting: What is Best Option And Why

Waterjet vs Laser vs Plasma

Plasma, laser or water cutting? Almost Everyone involved with metal fabrication has encountered this type of question. Though, there is no precise or certain answer to the question always being asked. It all counts on what you value most.

So to solve this difficulty people always face in choosing the best option here is a review of the economic and also technical qualities of both metal cutting solutions.

As with many things in the manufacturing world, there’s simply more than one way to embark on a particular job. This is very true especially when it comes to cutting raw material. Two of the most common techniques that you may find in shops around the world are water jets and plasma cutters.

While both of the machines are known for their ability to directly and easily cut through specific materials, there’s relatively a bit that distinguishes them in both their abilities and limitations.

How Water Jet Cutting Works

Waterjet vs plasma cutting : How Water Jet Cutting Works

The water jet is a cutting technique that depends on a combination of both water and abrasive to easily break down material along a given path Take it as a high-speed erosion.

The abrasive which is usually (garnet) is filled through a line into a mixing tube where it usually meets with the water source and is sprayed out with tremendous pressure (more than 50,000psi) to give a fine cutting stream at the tip of the ceramic nozzle.

The nozzle then moves along a path determined by the connected CNC software, at speeds that differ depending on the type and thickness of the material.

How Plasma Cutting Works

Waterjet vs plasma cutting : How Plasma Cutting Works

In this type, of technique instead of using water and abrasive, a plasma cutter operates using gas and electricity. The gas is forced through a compressed opening at very high pressure, at which point it gets in contacts with an electric arc that is sent through a nozzle.

This way it causes a reaction, and the gas which is usually (nitrogen, argon, oxygen, etc.) is heated to a particular degree that it enters into the fourth state of matter.

The plasma is so hot that it could melt through metal at a high speed that the excess material is cut off resulting in a moderately clean cut. Several types of gases can be used also depends on the type and thickness of the material.

Waterjet vs Plasma Cutting: Which One Do You Need And Why?

It best you go with a water jet because Water jet cutting is usually a cold process and does not set any heat into the material being cut. This means that there is no heat-affected zone created during the whole cutting operation.

This is considered to be a very vital fact for those working in the Aerospace industry, as the waterjet cutter does not alter the physical state of the material that is being cut or even cause the material to bend from the heat.

Furthermore, cutting through materials with the absence of a heat-affected zone (HAZ) helps with sheet metal fabricators as well. The removal of a heat affected zone implies that the whole process can go directly from the waterjet to threading or welding processes without the need to eliminate any heat-affected material.

This eventually helps to lessen labour and deliver a good quality product with speed and efficiency. And because water jet cutting is such a clean-cut, the need for softening or sanding around the edges of the material is not necessary.

Waterjet Vs Plasma Cutting: What Is Better For Your Business?

The Two main cutting techniques metal fabricators often use when cutting materials include laser cutting and water jet cutting. When it comes to getting a cutting machine for your business or just for your personal use, you can consider purchasing a laser, plasma, or waterjet cutter.

But depending on the type of material used and the desired result, it is therefore useful to know the differences between the two cutters so you need to first know the advantage and disadvantage of each of the cutters to know which best suit your business.

Each of these cutters has some advantages and disadvantages. Let’s take a brief look at them one after the other.

Pros and Cons of Waterjet Cutting:

Pros:

  • Can cut almost anything
  • Doesn’t generate any heat-affected zone (HAZ) which is good for cutting heat-sensitive materials.
  • Doesn’t give any hazardous fumes or waste.
  • Produces highly accurate cuts
  • Works flawlessly even on rough surfaces

Cons:

  • Abrasive materials are mainly very costly.
  • The cutting process creates a lot of noise if it is not done underwater.
  • Has slow cutting speed for most metals.

Pros and Cons of Plasma Cutting:

Pros:

  • Can cut a wide range of metals.
  • Easy to learn and operate.
  • Faster cutting speed.
  • Great hole quality.

Cons:

  • Produces huge heat-affected zones (HAZ).
  • It is less accurate compared to waterjet.
  • Can create micro fracturing to some metals during the cutting process.
  • Produces toxic fumes.

Waterjet vs Plasma Cutting Costs (Purchasing cost & Running/Operating cost)

The initial purchase price for plasma cutters is the cheapest compared to waterjet. The price of a plasma cutter may range from 15,000 USD to 300,000 USD. Though, most of the plasma cutters price below 100,000 USD. For a waterjet cutter, the cost is between 100,000 USD to 350,000 USD.

Read in More Detail: How Much Does Waterjet Cutting Cost

Other than the purchase price, plasma cutters are also inexpensive when it comes to operating costs. They cost roughly around 15USD/hour while waterjet cutters cost about 20 USD/hour.

Waterjet vs Plasma cutting – Common Uses

Waterjets can cut practically anything. But this type of cutter is generally used to cut heat-sensitive materials such as plastic or aluminium and when accuracy is of ultimate importance.

Also Read: What Materials Can a Waterjet Cut

Whereas plasma cutters have the lowest cut quality. These cutters are typically used in salvage and scrapping companies, automotive repair shops, metal fabrication shops, and also in some industrial constructions. So I hope with these few tips and ideas you get to know which is best for your business.

Do You Need Waterjet or Plasma Cutting? Here are Things You Should Know

waterjet cutting undeniably takes the lead when talking about quality, accuracy, and cost-efficiency.

Here are some things you should know.

  • No Chemicals or Heat

Because this technique requires only water and granite to cut the material therefore it is technically a cold cutting process and any heat that could be generated by the erosion process is quickly cooled by the water stream.

Hence, warping, misshaping and material hardening commonly associated with laser, plasma and machining is terminated, reducing the requirement for secondary processing.

It is much safer fo the operators and the environment as it does not produces any vapour or smoke and any dust particles created by the erosion process is trapped in the water and is later, filtered out safely later.

Recommended: 10 Waterjet Cutting Safety Tips For New Users

  • Versatility/Flexibility

As mentioned earlier on waterjet cutting is used in almost every industry because of its ability to cut almost any material considerably cheaply, all without altering the properties of the material. Materials ranging from 0.010″ acrylic to 10” thick stainless steel can also be cut by a water jet cutter. Thin materials can even be piled to enhance its productivity and lower costs.

These machines are accessible with different table sizes ranging from 0.5m x 1.5m to 2m x 4m, but some machines are custom made and could integrate big table sizes of 4m x 18m and run numerous heads.

  • Precision or near-net shape cutting

Tolerances tighter than +/- 0.005″ are conceivable when making use of the Q5 finish, particularly in thinner materials like 1″ stainless steel, and because the cutting speed can be altered mid-cut, it enables parts to have many edge qualities.

Things To Consider When Choosing Between Waterjet And Plasma Cutting

Having glanced at the definitions, advantages, and also disadvantages of each of the cutting method, it is now time to assess how they compare against each other.

  • Cost

Valuing purchasing cost, plasma cutting is the most cost-effective while laserjet is the most costly. For the operating cost, when you take into reference the materials being used for each machine, plasma will still score the lowest price with waterjet being the most costly.

  • Speed of Operation

The production rate of these metal cutters is determined by their cutting speeds.  The plasma jet is the fastest in terms of cutting and working speed. While waterjet is slow in terms of cutting speed (most especially on thick metals or materials)

  • Cutting edge quality

The accuracy of a cutting machine is normally determined by comparing the original measurements of the resulting part compared to the programmed part size. However, due to less heat distortion, the waterjet cutting machine is the most accurate, followed by plasma.

Choosing Between Waterjet Cutting Vs Plasma Cutting

Choosing the option between water jet cutting or plasma cutting gets down to the customer’s applications, tolerance,  budget and requirements.

Other aspects can be assessed, but for simplicity, concentrating on the customer’s application, productivity, tolerance, and operating cost needs will drive the discussion to the right solution. So have a look at both cutters stats below to know which best to choose.

Waterjet Stats

  • Materials that can be cut by a waterjet include steel, stainless steel, leather, composites, stone, tile, glass, food, paper, aluminium, textiles, rubber, foam, plastics. It can practically cut any material.
  • Waterjets normally are capable of cutting through metal thicknesses of about 6 inches and up to 18 inches on most of the materials.
  • Waterjet is usually a cold-cutting erosion technique that produces no heat-affected zone (HAZ) or any mechanical stress on the material (very important in the aerospace industry).
  • It creates a smooth edge – no secondary processing required on the material.
  • Able to create detailed cut – intricate shapes can be made.
  • It can also be a bit messy cutting process.

Plasma Stats

  • Materials that can be cut by a Plasma cutting machine include mild steel, carbon steel, copper, stainless steel, aluminium, and other metals.
  • A plasma cutter can be used on metal that is in any condition (rusted, painted or grated).
  • Most of the productive cutting process on steel is normally from 1/4 inch to 2 inches in thickness.
  • It covers thicknesses ranging from 2–3 inches, depending on the material.
  • Some rubbing may be required for slag removal around the heat-affected zone (HAZ); High definition plasma reduces the amount of slag.
  • Plasma cutters are highly automated making them much easy and simple to use for the operator.
  • The cut quality and accuracy are not as detailed as a waterjet cutting solution.

Conclusion

When it gets to determine the best among water jet and plasma cutters, there’s no clear winner. Because there are just too many variables involved that you’ll need to assess before choosing any one of them.

And am sure this article provides you with a quick overview of the relative comparison between these two different cutters so that you can choose or decide for yourself. But, the result will solely depend on your priorities.

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